I notice from your grandad's service record at the end of 1944 whilst he was in HBL RM Commando, his CO was W W Glover, the same as my father's who was in MNBDO1 and prior to that your grandad was at HBL RM Training Group. Maybe they might have come across each other. Unfortunately, I cannot help with your other questions as I am still learning myself but wish you good luck with your research.